It was the simplest of words, but one that Lance Armstrong had never been able to bring himself to say when faced with doping allegations. But when he answered "yes" to each of American talk show host Oprah Winfrey's first five questions, a giant step towards reaching a final resolution to the biggest doping scandal in world sport had been made.

In the first part of the two-hour show aired on Discovery Channel and on Winfrey's cable network OWN, Armstrong admitted to having used erythropoietin (EPO), testosterone, human growth hormones, cortisone and having blood transfusions en-route to winning seven Tours de France.

He denied doping during his comeback years from 2009 to 2011, during which he raced the Tour twice more without winning.

The interview raised many more questions that many observers will hope will be answered in part two of the interview, which will air on Saturday at 1pm Sydney time, especially concerning the alleged ring of doping operations – how far it really extended and who else might be implicated. Most interesting was how Armstrong accepted, even embraced, his role in doping and his attempt to convince the worldwide audience that he accepted his guilt.

It remains to be seen how sincere he really was, although it was clear during the interview that he felt uncomfortable on several issues, in particular the involvement of Italian doctor Michele Ferrari, who was on the United States Anti-Doping Agency charge sheet with Armstrong and has been banned for life. Armstrong was also unwilling to speak in depth about his relations with Betsy Andreu, the wife of former teammate Frankie Andreu, other than to say that he had spoken to them both recently in an attempt to mend bridges. He conceded that a 40-minute talk could not achieve that.

However, Armstrong did say that he owes an apology to Emma O'Reilly, his former soigneur – or masseuse – on the US Postal Services team for his treatment of her. No doubt, there is a string of aggrieved parties who have suffered as a result of Armstrong's doping operations and behaviour.

When part one of the interview with Winfrey finished, among the topics promoted to be discussed in the next instalment were the fallout with his sponsors, and the reaction from the cancer community and his family. But there are many more issues the world wants addressed.